This invention relates generally to plug devices, and more particularly concerns a plug especially adapted for use in retaining insulation inside the cavities of refrigerators and like appliances.
In the manufacture of double-walled appliances such as insulated refrigerators and the like, modern practice calls for preliminary assembly of an outer shell and an inner shell to form a hollow cavity. After the cabinet defined by these shells has been assembled, a foaming resin mixture, such as polyurethane foam, is introduced into the cavity between the shells. This is often accomplished by conducting the foaming insulation material along a tube and nozzle through an aperture or hole formed in the outer cabinet shell. To present a neat, finished appearance to the appliance, and to prevent an outflow of insulating material, a plug is emplaced in the shell aperture.
Some plugs offered to accomplish these purposes have been of the prior-placement variety; that is, they have been designed to be installed in an appliance shell wall prior to introduction of insulation into the cavity. These plugs accommodate an insulation-delivering nozzle, and after the conduit has been withdrawn, the plug retains the emplaced material behind the outer cavity wall.
It is the general object of the present invention to provide a cavity closure plug for home appliances and the like which is less expensive yet more effective than those previously offered.
A more specific object of the invention is to provide a filler plug of the type described which can be opened to permit introduction of material behind the plug-associated wall without the user paying particular attention to the plug and its structure. An associated object is to provide such a plug which can be used without requiring the use of special tools or use techniques.
Another object is to provide such a plug which will afford a secure, permanent seal after the plug has been opened and material has been emplaced behind the wall.
Yet another object is to provide such a plug which can be easily installed by even relatively inexperienced personnel using inexpensive, simple tools.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.